Ventifacts - sculptured by the wind - a ventifact tells its story
My Story - my life as a ventifact
I'm a ventifact, that is a rock sculpted and shaped by the wind. I was
found in the deserts of Central Australia.
Of course the wind blows lots of sand and dust that over a long period of
time creates flat and curved surfaces on me.
See me in the image below...
In order for a ventifact like me to be created you need a place with a
fairly hard surface and a wind that blows sand and dust from the same
direction for most of the year...
What you see is not always what you get!
What you see on the outside is not always what you find on the inside for
example all the ventifacts below are from eastern Iran.
All are the same rock on the inside but have different colours and
textures on the outside.
The external colours are caused by "Desert Varnish" which results
when the fresh sandblasted surface of the rock chemically reacts with
minerals in the blowing dust...
different dusts gives different colours
and different size sand grains give different textures...
What do the shapes mean?
You get a flat shape facing the wind
You get a concave (curved inwards) face caused by an eddy on the
downwind side
Wearing away to sand...
As the rock wears away over long periods of time it becomes unbalanced and
is tipped or blown over and becomes a smaller elongated core...finally
becoming just a bit more of the blowing sand...